Before we start I have to throw out props to Eschelon, NxtGenCowboy, Virus, Ziggy471 and of course to the wifi-tether guys as well as cyanogen for the needed source/binaries (pre-11/18 versions) which allowed me to find the right path to get this 100% working. Also had awesome testers proxhack / jlmr731 and especially joshbeach. They all were essential to getting this all working. I still don't have a GS3 so poor Eschelon/NxtGenCowboy probably wiped/installed about 100 builds before this worked (and after when I lost source... grumble). Thanks to everyone that helped.

Legal/GPL Stuff
Carriers hate tethering, you all know that. Use at your own risk/with common sense & dont blame me for anything that goes wrong

WifiTether is under the GPLv3 license, so below is the source for the mods

-Device-Profile: Leave this on auto (default)
-Netdndc Max Client Cmd: Required for GS3ish devices. If not enabled you will likely get an AP but cannot connect.
-MSS clamping: on (default)
-Routing fix: on (default)

Heres some geek details on basic binaries how the backend of wifi-tether works. The main modes I played with and required files are as detailed below:

New OptionsFramework Tether(Fallback)
Use this if you have issues with wifitether mode. It forces on a wifihotspot using just framework. This has been reported to not throw up the paywall nag screen on some devices/carriers but YMMV. It may be able to be used nonroot as well if you ignore the initial warning.

Send NetdNDC Max Client CMD
This modifies the standard ndc command string to add in the Max Client parameter. More details are in post here

Wifi-Driver reload
This is the standard driver reload for wifi tether. It runs inside one script "./tether start|stop".

Wifi-Driver reload 2
This is a modified command that reloads firmware in a separate su request before the tether-edify code is run. May require SuperSU.apk

Use Cyanogen Hostapd Binary
This is the old method and is totally removed stating with the 11/20 update

The hostapd binary contained in atleast touchwiz JB contains extra fields explained above. If the extra commands are not working on X device you can try to fall back to this binary. This uses a dirty hack which installs hostapd and symlinks between versions for native or WifiTether mode. As long as you start and stop wifitether things should always line up. If you get into an issue where you crash things might get out of sync but should fix themselves next toggle of wifi tether. I have also added in menu items for the gs3 to manually swap binaries around.

*You must have a proper setup busybox for the GS3 code to work right. It moves system files around - you might win a reflash if things really go bad*
*Cyanogen Hostapd Symlink option only*- Make a system backup, it modifies sys files so theres a chance it will break something

Bugs

You might have to toggle stuff on and off once first if you run into errors. I think there's an error on first creation of config

If you switch modes between native wifitether and fallback mode (or stock tethering), your phone may spontaneously combust(wifi crashes) after the routing mess that ensues. Just reboot and you'll be all set again.

Seems to work better on SuperSU - Probably due to the per-app permissions vs per command.

Download:**EVERY BUILD YOU MUST UNINSTALL OLD VERSIONS FIRST OR ATLEAST CLEAR APP DATA, IT DOES NOT UPGRADE NICELY**
-If you have problems, scroll down and read FAQ in post2 before posting

Try to merge together what worked for everyone across different devices. There are 2 options in settings with mild enhancements
-Wifi-Driver Reload - Driver reload inside of tether script. Similar to 11/20 version
-Wifi-Driver Reload 2 - Driver reload outside of tether script. Similar to 11/18 version

Please report in with Carrier/Device and what option works best for you. Valid combinations are no reloads checked or one of the reload methods. Do not check both (theres no code to stop you from doing it now)
There is no code differences between the two apk versions, I just recently added in reload method 2 so rom devs can cook in whatever apk just works without changing settings.

Quote:

Apparently I botched code along the line somewhere between 18-20. Please let me know which one of these versions you are on and what works.

WifiTether_TrevE_Mod_11_20_2012_insmodv3.apk - If v2 doesnt work this should - http://www.androidfilehost.com/?fid=9390169635556426691
If insmod v2 doesnt work, insmod v3 switches to insmod on load, rrmod to unload, then reloads the driver when finished with with mfgloader -u / mfgloader -l
WifiTether_TrevE_Mod_11_20_2012_insmodv2.apk - Hopefully working- http://www.androidfilehost.com/?fid=9390169635556426686
Driver Reload did not like loading with mfgloader in original build. This switches to insmod on load, mfgloader/rrmod to unload, then reloads the driver when finished with mfgloader -u / mfgloader -l

cut down symlinks to only move hostapd around.
Made a checkbox that controls symlink code. Trying to axe it all. Moved this and fallback to settings screen. now save/load
define wifi.interface where it is undefined like on t0ltespr (hack to wire it to ndc settngs)
try to work with t0ltespr's /lib/ directory
cut down root code significantly (hopefully spam/timing issues resolved)

Phone takes back control of wifi- Youll notice a "What the hell" toast message. Somehow the phone moved wifi state, either you toggled an app that turns on wifi or some system process was thinking for you. Disable whatever is doing it.

XXXX still doesnt work - First try SuperSU. This will avoid a lot of headaches. Then make sure you are on latest version and that you have uninstalled/cleared app data when you went to a newer version. Read over the last few pages of thread at least too to make sure its not a known issue then go for it and post away. Make sure you include Carrier / Device / Rom / SU application.

Debugging Issues

For those people having issues on other gs3 like devices / roms / whatever I do not even have a gs3 so this is all blind. To try to help debugging I created a script to hopefully grab information needed. This should help from both working/nonworking devices to help eliminate the stupid symlink code and fix up other devices.

The scripts point is to try to get a working AP. If you can post how you did it and we can get source changed. By default it does no driver reloads and starts an Open AP with SSID TrevScript.

First grab the latest script from svn (ill update it with more info after I get some logs so make sure you have latest)

Examples:
Make sure wifi is on but do not start witfitethering. All you want to do is run "Set Binaries to WifiTether" option in the menu of app to start with a known working base then follow below code

try no encryption with insmod where your wifi module is /system/lib/modules/dhd.ko

Code:

adb shell su -c tetherdebug.sh NONE insmod /system/lib/modules/dhd.ko

try no encryption with mfgloader where your wifi module is /system/lib/modules/dhd.ko

try wpa2 (password is Trev) with insmod where your wifi module is /system/lib/modules/dhd.ko

Code:

adb shell su -c tetherdebug.sh WPA2 insmod /system/lib/modules/dhd.ko

There shouldn't be personal information in the debug logs, the most I can think of that would be displayed is if you have an encryption passphrase set in wifitether. Sending the 2 files named with what mode you were in will help get it going elsewhere and hopefully kill the symlink code

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